In recent years, information treating apparatuses such as personal computers, portable telephones and personal digital assistances (PDA) are requested not only to be quick in data processing, small in size, light in weight but also to be suitable for switching among plural applications. On the other hand, control apparatuses such as robots are requested to be controllable by switching plural control algorithms in real time. From such a viewpoint, circuit substrates are demanded in which the circuit is reconfigurable, especially those in which the circuit is reconfigurable at a high speed in real time.
Conventionally, efforts are made to develop such a circuit by improvement of electronic circuits, switches, memories, and the like. However, with the increase of the processing speed, problems arise such as wiring delay, and EMI (electro-magnetic interference). In one method for avoiding such disadvantages, optical wiring is used which has advantages of high-speed transmission and no electromagnetic induction inherently.
U.S. Pat. No. 5,357,122, for instance, discloses an optical-electronic integrated circuit device capable of three-dimensionally transmitting optical signals between plural semiconductor substrates on each of which an integrated circuit is previously formed.
U.S. Pat. No. 5,191,219 discloses an information processing apparatus, which comprises means forming a planar optical waveguide which extends in two dimensions and serves as a shared medium, a plurality of light-emitting means and a plurality of light-detecting means extending in a two dimensional arrangement over said planar optical waveguide for broadcasting light signals and abstracting light signals, respectively, into and from said planar optical waveguide, and a plurality of subsystems including input and output ports for processing the light signals in the shared medium, the light-detecting means being couples to input ports and the light-detecting means being coupled to output ports of the subsystems.
However, the optical wirings employed in the above cited references and other prior art techniques are not sufficient in the flexibility in optical wiring formation.